Sofia Jarvis, 4, of Berkeley, Calif., was struck by a polio-like illness when she was 2. It left her with a paralyzed arm. / Jessica Tomei

by Elizabeth Weise, USATODAY

by Elizabeth Weise, USATODAY

A mysterious polio-like syndrome has affected as many as 25 California children, leaving them with paralyzed limbs and little hope of recovery.

"What's we're seeing now is bad. The best-case scenario is complete loss of one limb, the worst is all four limbs, with respiratory insufficiency, as well. It's like the old polio," said Keith Van Haren, a pediatric neurologist at Lucile Packard Children's Hospital in Palo Alto, Calif.

The first known case appeared in 2012. Sofia Jarvis in Berkeley began to experience wheezing and difficulty breathing. The 2-year-old spent days in the intensive care unit at Children's Hospital Oakland. Doctors thought she had asthma.

"As we were leaving the doctor's office, I noticed that she went to grab something with her left arm and she stopped, midway," Tomei said.

Eventually Sofia was brought to Van Haren's clinic with "a unique set of symptoms." She was treated with steroids and intravenous immunoglobulin therapy, used to reduce the severity of infections by giving the body antibodies to protect against bacteria and viruses. "None of it helped," said Van Haren, a neurology professor at the Stanford University School of Medicine.

"He told us right away that the prognosis was really poor and that she's not going to get better," Tomei said.

The diagnosis proved correct. Today, at age 4, Sofia's left arm is paralyzed and she has some weakness in her left leg as well as slight breathing issues.

Still, parents shouldn't panic. "This is really very rare," Van Haren said. "But we are asking any families who notice a sudden onset of weakness to see their doctors immediately. Their doctors should contact the California Department of Public Health."

California is working with the Centers for Disease Control and Prevention in Atlanta to see if there are cases outside California. So far none have been reported.

Overall Sofia's family is grateful. "She's still with us, she's still running around, she's going to preschool," her mother said.

The case galvanized Van Haren and other neurologists, who worried a new disease had appeared. When they began to go through recent medical files, they found two more cases, both in the San Francisco Bay area.

"We don't have a final case count, but it's probably in the neighborhood of 25 cases, all in California," said Van Haren. The median age of those stricken is 12.

"The California Department of Public Health has asked health care providers to report any polio-like cases they might identify and send specimens so that we can better assess the situation," said Carol Glaser, chief of the encephalitis and special investigation section of the California Department of Public Health in Sacramento.

The children don't have polio, but their symptoms look much like the disease that terrified generations of parents beginning in the 1890s.

Patients lose the ability to move their arms or legs, which "just dangle, like empty balloons," Van Haren said. Because the children can't move their limbs, the muscles atrophy and the limb shrivels.

Polio is a highly infectious disease caused by the polio virus. It invades the nervous system and in one in 200 cases causes irreversible paralysis, according to the World Health Organization. It was not until the introduction of the Salk vaccine in 1954 that any protection against it was available.

Testing confirmed that the children in California "definitely do not have polio," Van Haren said.

"The cause of most of these cases is not known. Some clinical and laboratory features, such as the pattern of inflammation seen in the spinal cord on MRI, are consistent with a viral process," said Glaser.

Van Haren suspects the culprit is an enterovirus. That is a family of viruses that includes polio but also the milder hand, foot and mouth disease, common in infants and children.

Unfortunately while there's a vaccine for the polio virus, "we don't have vaccines for the other enteroviruses," Van Haren said.

"In the past decade, newly identified strains of enterovirus have been linked to polio-like outbreaks among children in Asia and Australia," he said. The California cases highlight the possibility of an emerging infectious polio-like syndrome in California.

While there haven't been reports of the illness outside California, Van Haren thinks that's only because no one is looking for it. He believes once doctors nationwide begin to, they'll find other cases.

"My goal is to get the word out to other neurologists, to make them aware of this," he said.

The Stanford group will be presenting a case report at the American Academy of Neurology meeting in Philadelphia in April.

Tomei wants parents to be aware of this new outbreak because it took so long for doctors to think of polio or polio-like diseases in Sofia's case

"The younger doctors have just never seen polio," she said. "Maybe collaborating between the younger generation and the older generation who actually went through polio will help us catch more cases."